1. Field
The present disclosure relates to methods and apparatuses for acquiring a spin echo signal by using a radio frequency (RF) pulse and a gradient magnetic field.
2. Description of Related Art
A magnetic resonance imaging (MRI) system may be an apparatus for acquiring a sectional image of a part of an object by expressing, via a contrast comparison, a strength of a magnetic resonance (MR) signal with respect to a RF signal generated in a magnetic field having a specific strength. For example, if an RF pulse that resonates only a specific atomic nucleus (for example, a spinning nucleus) is emitted for an instant toward the object placed in a strong magnetic field and then the emission stops, an MR signal is emitted from the specific atomic nucleus, and thus, the MRI system may receive the MR signal and obtain an MR image. The MR signal may denote an RF signal emitted from the object. An intensity of the MR signal may be determined according to a density of a predetermined atom (for example, hydrogen) in the object, a T1 relaxation time, a T2 relaxation time, a flow of blood, or the like.
MRI systems have characteristics different from those of other imaging apparatuses. Unlike imaging apparatuses such as computed tomography (CT) apparatuses that acquire images according to a direction of detecting hardware, MRI systems may acquire 2D images or 3D volume images oriented toward an optional point. MRI systems do not expose objects or examiners to radiation, unlike CT apparatuses, X-ray apparatuses, position emission tomography (PET) apparatuses, and single photon emission CT (SPECT) apparatuses, may obtain images having high soft tissue contrast, and may also acquire neurological images, intravascular images, musculoskeletal images, and oncologic images that are required to clearly show abnormal tissues.